I've currently got a situation in my PC where I have 3 devices that connect to the motherboard via the onboard USB pinouts.

The problem is, I only have two sets of USB pinouts on my motherboard.

Is there any way of connecting two devices to one set of pinouts? Essentially, I'm looking for the functionality of a USB hub, but I'd like it to be inside the case, and provide pinouts rather than regular USB ports.

Update: I don't need any more USB ports, I have devices that use the USB pinouts. I already have extra USB ports that aren't used, so adding an PCI USB card doesn't really help anything.

4 Answers
4

You could go about this a couple ways. The easiest is to buy a cheap $10 usb card with another usb header on the card that you could connect to. This way you do not jerry rig anything and do not endanger us all. ;):

Good info but I don't need any more USB ports, I have plenty, so the addon card doesn't help at all. I need more PINOUTS. The adapter you linked might work, but I'd prefer something totally internal if possible.
–
TM.Aug 17 '09 at 3:06

TM. The card linked above has two USB headers (which I think you are calling PINOUTS).
–
hanleypAug 17 '09 at 3:23

Yah, I know you don't need more USB ports, but that card comes with an extra on-board "USB pinout" as you are calling them. It makes it really easy and you don't have to do any extra soldering or splitting wires. You also will not run into the power problem hyperslug mentioned. It is cheap, reliable, safe, and very quick. Also, look at the pictures on that newegg card and you will see what I mean.
–
TroggyAug 17 '09 at 4:08

But if one or both devices draw power
FROM the USB header then the wheels
fall off. A device connected to the
USB header will hang onto the
connection even if the software for it
is shut down and the device is
"powered off."

Another option is an internal USB expander -- this is basically a hub that connects to internal power and a single motherboard USB header, and provides multiple USB headers and possibly some internal ports.

You would have to use a hub to connect two devices to one USB header. One 4 or 5-pin USB header = 1 USB port.

Two devices on one USB port cannot work reliably at the same time. The reason for this is (this is from memory, so it may be a little out off or missing steps):

Once a device is plugged in, it performs a hardware handshake with the controller.

The controller then tells the OS that a device was plugged in.

The OS detects what the device is and loads the correct drivers.

The driver polls the device periodically to see if there is anything to communicate and performs the transactions until the device is removed.

USB is a very host software driven interface compared to other I/O. If a second device is connected to the same wires, it could potentially cause the first device to disconnect, cause errors in the transactions, or take over the connection.

Another problem is each USB port is limited by specification to be able to supply 5V @ 0.5A max current. If two devices draw power off the port, it could trip the overcurrent sense or a resettable fuse causing the port to fault.

This is factual but doesn't address the question. I realize all of this and in fact in the question I mention that I need a hub specifically. I'm just wondering if an internal hub even exists for purchase or can be built relatively easily.
–
TM.Aug 17 '09 at 3:11

So you have 3 internal USB devices with plugs and go onto the headers, but only have 2 internal headers? It is pretty easy to solder a USB plug to a header. I'll look for hubs which have headers. Usually they only are provided on a mother board and hubs have type-A plugs.
–
hanleypAug 17 '09 at 3:17

Soldering is easy if you have a soldering iron and solder, that is.
–
hanleypAug 17 '09 at 3:18